Semiconductor device including internal voltage generation circuit

ABSTRACT

A semiconductor integrated circuit device has a negative voltage generation circuit provided at each power supply circuit unit for six memory macros. Therefore, the response with respect to variation in a negative voltage is increased. In a standby mode, a negative voltage supply line for the six memory macros is connected by a switch circuit, and only a negative voltage generation circuit of one power supply circuit unit among six negative voltage generation circuits of the six power supply circuit units is rendered active. Thus, increase in standby current can be prevented.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to semiconductor devices, particularly asemiconductor device including an internal voltage generation circuit.

2. Description of the Background Art

In a general DRAM (Dynamic Random Access Memory), an N channel MOStransistor is used as a transfer gate of a memory cell. A positivevoltage is employed as the voltage for selection, applied to a wordline, when a memory cell is rendered active. A negative voltagegeneration circuit generating a negative voltage lower than the groundvoltage is incorporated in this DRAM. The negative voltage is used as asubstrate bias voltage to control the substrate effect of a transistor.

In this context, variation in the level of the negative voltage issuppressed due to the large capacitance of the substrate. Further,high-speed response at the negative voltage generation circuit formed ofa negative voltage detection circuit and a negative charge supplycircuit is not required. Since high-speed response at the negativevoltage generation circuit is not required even for a chip thatincorporates a plurality of memories, only one negative voltagegeneration circuit having a performance level just required to chargethe substrate when the external power supply is turned on is disposed atone site.

In a DRAM using a P channel MOS transistor as the transfer gate of amemory cell, a negative voltage is used as the voltage for selection,applied to a word line, when a memory cell is rendered active. In thistype of DRAM, it is required to write a signal of ground level into amemory cell in a write operation mode, and output a signal voltage ofsufficient amplitude from a memory cell in a readout operation mode.Therefore, the voltage to select a word line must be set sufficientlylow.

In this context, high-speed response at the negative voltage generationcircuit is required since the substrate capacitance is not large as in aconventional DRAM and the current consumption related to negativevoltage is increased. Thus, there is a problem that variation in thenegative voltage becomes great in a chip that has one negative voltagegeneration circuit incorporated for a plurality of memories.

A possible consideration is to increase the through current (standbycurrent) flowing to the negative voltage detection circuit in thenegative voltage generation circuit to allow higher speed in response.However, the standby current cannot be increased in the field ofbattery-driven portable equipment in which this type of DRAM isincorporated, since there is a demand for lower power consumption byreduction in operating voltage and consumed current.

This type of DRAM also poses the problem of increase in circuit failurecaused by excessive stress applied to the transistor during a burn-intest mode.

Further, this type of DRAM poses the problem that the operation speed isreduced due to the reduction in power supply voltage and/or increase inground voltage in a circuit operation mode.

In addition, this type of DRAM is easily affected by noise.

Moreover, there was a problem that a semiconductor integrated circuitdevice including a plurality of such DRAMs exhibited unstable circuitoperation due to the reduction in power supply voltage and/or increasein ground voltage.

SUMMARY OF THE INVENTION

In view of the foregoing, a main object of the present invention is toprovide a semiconductor device that allows high-speed operation with lowstandby current.

Another object of the present invention is to provide a semiconductordevice that can prevent application of excessive stress in a burn-intest mode.

A further object of the present invention is to provide a semiconductordevice having high operation speed.

Still another object of the present invention is to provide asemiconductor device highly immune to noise.

A still further object of the present invention is to provide asemiconductor device with small reduction in power supply voltage andincrease in ground voltage.

A semiconductor device according to the present invention includes aplurality of negative voltage supply lines connected in common; aplurality of negative voltage detection circuits provided correspondingto the plurality of negative voltage supply lines, respectively, eachproviding a first activation signal when a voltage of a correspondingnegative voltage supply line is higher than a predetermined negativevoltage; a plurality of negative charge supply circuits providedcorresponding to the plurality of negative voltage supply lines,respectively, each supplying negative charge to a corresponding negativevoltage supply line when the first activation signal is output from acorresponding negative voltage detection circuit; a plurality of memorycircuits provided corresponding to the plurality of negative voltagesupply lines, respectively, each receiving a negative voltage from acorresponding negative voltage supply line, and allowing a datawrite/read operation independently; and a control circuit renderingactive a first number of negative voltage detection circuits among theplurality of negative voltage detection circuits in an active mode, andrendering a second number of negative voltage detection circuits, lowerin number than the first number, active in a standby mode. Therefore,reduction in current consumption in a standby mode and increase in theoperation speed in an active mode can be facilitated.

A semiconductor device according to another aspect of the presentinvention includes a plurality of negative voltage supply lines; aplurality of negative voltage generation circuits provided correspondingto the plurality of negative voltage supply lines, respectively, eachrendered active in a normal operation mode to maintain a correspondingnegative voltage supply line at a predetermined negative voltage, andrendered inactive in a burn-in test mode; a voltage switch circuitprovided common to the plurality of negative voltage supply lines toprovide a ground voltage to a plurality of negative voltage supply linesin a burn-in test mode; and a plurality of memory circuits providedcorresponding to the plurality of negative voltage supply lines,respectively, each receiving the negative voltage and the ground voltagefrom a corresponding negative voltage supply line. Thus, application ofexcessive stress in the burn-in test mode can be prevented.

A semiconductor device according to a further aspect of the presentinvention includes a reference voltage generation circuit generating areference voltage; a reference voltage line receiving the referencevoltage generated at the reference voltage generation circuit; a shieldline provided along the reference voltage line; a power supply voltageline receiving power supply voltage; a stabilization capacitor havingone electrode connected to the reference voltage line and the otherelectrode receiving the power supply voltage from the power supplyvoltage line; a negative voltage generation circuit driven by the powersupply voltage from the power supply voltage line, and receiving thereference voltage from the reference voltage line to generate a negativevoltage based on the received reference voltage; and an internal circuitdriven by the power supply voltage from the power supply voltage lineand the negative voltage generated at the negative voltage generationcircuit. Since the negative voltage is reduced as the power supplyvoltage is reduced, the voltage applied to the internal circuit will notchange. Accordingly, the operation speed will not vary.

A semiconductor device according to still another aspect of the presentinvention includes a reference voltage generation circuit generating areference voltage; a reference voltage line receiving the referencevoltage generated at the reference voltage generation circuit; a shieldline provided along the reference voltage line; a ground voltage linereceiving a ground voltage; a stabilization capacitor having oneelectrode connected to the reference voltage line and the otherelectrode receiving the ground voltage from the ground voltage line; aninternal voltage generation circuit driven by the power supply voltageand the ground voltage from the ground voltage line, and receiving thereference voltage from the reference voltage line to generate aninternal voltage based on the received reference voltage; and aninternal circuit driven by the internal voltage generated at theinternal voltage generation circuit and the ground voltage from theground voltage line. Since the internal voltage rises as the groundvoltage rises, the voltage applied to the internal circuit does notchange. Therefore, the operation speed will not vary.

A semiconductor device according to a still further aspect of thepresent invention includes a reference voltage generation circuitgenerating a reference voltage; a reference voltage line receiving thereference voltage generated at the reference voltage generation circuit;a shield line provided along the reference voltage line, and receiving aground voltage; an internal voltage generation circuit receiving thereference voltage from the reference voltage line to generate aninternal voltage based on the received reference voltage; and aninternal circuit driven by the internal voltage generated at theinternal voltage generation circuit. The provision of a referencevoltage generation circuit, reference voltage line, shield line andinternal voltage generation circuit in each internal circuit allowsreduction in the resistance of the shield line. Therefore, the effect ofnoise on the shield line can be alleviated.

A semiconductor device according to yet a further aspect of the presentinvention includes a reference voltage generation circuit generating areference voltage; a reference voltage line receiving the referencevoltage generated at the reference voltage generation circuit; a shieldline provided along the reference voltage line, and receiving a groundvoltage; a plurality of internal voltage generation circuits arranged inan extending direction of the reference voltage line, each receiving thereference voltage from the reference voltage line to generate aninternal voltage based on the received reference voltage; and aplurality of internal circuits provided corresponding to the pluralityof internal voltage generation circuits, respectively, each driven bythe internal voltage generated at a corresponding internal voltagegeneration circuit. Since a reference voltage generation circuit,reference voltage line, and shield line are provided common to theplurality of internal voltage generation circuits, the layout area isreduced.

A semiconductor device according to yet another aspect of the presentinvention includes a reference voltage generation circuit generating areference voltage; a reference voltage line receiving the referencevoltage generated at the reference voltage generation circuit; aplurality of internal voltage generation circuits arranged in anextending direction of the reference voltage line, each receiving thereference voltage from the reference voltage line to generate aninternal voltage based on the received reference voltage; a plurality ofshield lines provided corresponding to the plurality of internal voltagegeneration circuits, respectively, each provided along the referencevoltage line, and receiving a ground voltage; and a plurality ofinternal circuits provided corresponding to the plurality of internalvoltage generation circuits, respectively, each driven by the internalvoltage generated at a corresponding internal voltage generationcircuit. Since a reference voltage generation circuit and referencevoltage line are provided common to the plurality of internal voltagegeneration circuits, the layout area is reduced. Further, since a shieldline is provided for each internal voltage generation circuit, theeffect of noise on the shield line can be alleviated.

A semiconductor device according to yet a still further aspect of thepresent invention includes a substrate having a surface divided into aplurality of regions in a first direction; a plurality of memorycircuits provided at the plurality of regions, respectively; a pluralityof power supply voltage lines provided corresponding to the plurality ofmemory circuits, respectively, each extending in a second directionorthogonal to the first direction, supplying a power supply voltage to acorresponding memory circuit; and a plurality of ground voltage linesprovided corresponding to the plurality of memory circuits,respectively, each extending in the second direction, and supplying aground voltage to a corresponding memory circuit. Since a power supplyvoltage line and ground voltage line are provided for each memorycircuit, reduction in the power supply voltage and increase in theground voltage can be suppressed.

According to the present invention set forth above, a semiconductordevice that allows high-speed operation with low standby current can beprovided. Further, a semiconductor device that can prevent applicationof excessive stress in a burn-in test mode can be provided. In addition,a semiconductor device having high operation speed can be provided.Further, a semiconductor device highly immune to noise can be provided.Additionally, a semiconductor device with small reduction in powersupply voltage and increase in ground voltage can be provided.

The foregoing and other objects, features, aspects and advantages of thepresent invention will become more apparent from the following detaileddescription of the present invention when taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a configuration of a semiconductorintegrated circuit device according to a first embodiment of the presentinvention.

FIG. 2 is a circuit block diagram of a configuration of the negativevoltage generation circuit shown in FIG. 1.

FIG. 3 is a block diagram of a configuration of the reference voltagegeneration circuit generating reference voltage shown in FIG. 2.

FIG. 4 is a timing chart indicating an operation of the negative voltagegeneration circuit shown in FIG. 2.

FIG. 5 is a circuit diagram of a configuration of a memory cell in thememory macro shown in FIG. 1.

FIG. 6 is a circuit diagram of a configuration of a word line driverunitary circuit in the word line driver shown in FIG. 1.

FIG. 7 is a sectional view of a configuration of a memory cell arrayincluding the memory cell shown in FIG. 5.

FIG. 8 is a block diagram of a modification of the first embodiment.

FIG. 9 is a block diagram of another modification of the firstembodiment.

FIG. 10 is a further modification of the first embodiment.

FIG. 11 is a block diagram to describe a problem in this type ofsemiconductor integrated circuit device.

FIG. 12 is a block diagram of a configuration of a semiconductorintegrated circuit device according to a second embodiment of thepresent invention.

FIG. 13 is a block diagram to describe a problem in this type ofsemiconductor integrated circuit device.

FIG. 14 is a timing chart indicating an operation of the semiconductorintegrated circuit device shown in FIG. 13.

FIG. 15 is a block diagram of a main part of a semiconductor integratedcircuit device according to a third embodiment of the present invention.

FIG. 16 is a timing chart indicating an operation of the semiconductorintegrated circuit device shown in FIG. 15.

FIG. 17 is a block diagram to describe a problem in this type ofsemiconductor integrated circuit device.

FIG. 18 is a block diagram of a configuration of the comparator shown inFIG. 17.

FIG. 19 is a timing chart indicating an operation of the semiconductorintegrated circuit device shown in FIG. 17.

FIG. 20 is a block diagram of a main part of a semiconductor integratedcircuit device according to a fourth embodiment of the presentinvention.

FIG. 21 is a timing chart indicating an operation of the semiconductorintegrated circuit device shown in FIG. 20.

FIG. 22 is a block diagram of a configuration of a semiconductorintegrated circuit device according to a fifth embodiment of the presentinvention.

FIG. 23 is a circuit diagram of a reference voltage line and shield linein the semiconductor integrated device shown in FIG. 22.

FIG. 24 is a block diagram of a configuration of a semiconductorintegrated circuit device according to a sixth embodiment of the presentinvention.

FIG. 25 is a circuit diagram of a reference voltage line and shield linein the semiconductor integrated circuit device shown in FIG. 24.

FIG. 26 is a circuit diagram of a modification of the sixth embodiment.

FIG. 27 is a circuit diagram of another modification of the sixthembodiment.

FIG. 28 is a block diagram to describe a problem in this type ofsemiconductor integrated circuit device.

FIG. 29 is a block diagram of a configuration of a semiconductorintegrated circuit device according to a seventh embodiment of thepresent invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment

Referring to FIG. 1, a semiconductor integrated circuit device accordingto a first embodiment of the present invention includes a semiconductorsubstrate 1, a plurality (six in the drawing) of memory macros M1-M6formed at the surface of semiconductor substrate 1, each for a datawrite/read operation independently, six power supply circuit units P1-P6provided corresponding to memory macros M1-M6, respectively, negativevoltage supply lines L0-L6 and switch circuits SW2-SW6 for supplying anegative voltage VNEG generated at a negative voltage generation circuit2 in each of power supply circuit units P1-P6 to a word line driver 3 inmemory macros M1-M6, and a control circuit 4 generating control signalsACT1-ACT6 and φ2-φ6.

Negative voltage supply line L0 is arranged at the middle ofsemiconductor substrate 1, extending in the Y direction (verticaldirection) in the drawing. Memory macros M1, M3 and M5 are arranged inthe Y direction at the left side of negative voltage supply line L0.Power supply circuit units P1, P3 and P5 are arranged at the left sideof memory macros M1, M3 and M5, respectively, adjacent thereto. Memorymacros M2, M4 and M6 are arranged at the right side of negative voltagesupply line L0, opposite to memory macros M1, M3, and M5, respectively.Power supply circuit units P2, P4 and P6 are arranged at the right sideof memory macros M2, M4 and M6, respectively, adjacent thereto. Negativevoltage generation circuit 2 in each of power supply circuit units P1-P6is rendered active when a respective one of control signals ACT1-ACT6 isdriven to an activation level to supply a negative voltage to negativevoltage supply lines L1-L6, respectively.

Each of negative voltage supply lines L1-L6 extends in the X direction(lateral direction) in the drawing. Negative voltage supply line L1 isconnected between negative voltage generation circuit 2 of power supplycircuit unit P1 and a word line driver 3 of memory macro M1, and has oneend connected to negative voltage supply line L0. Negative voltagesupply line L2 is connected between negative voltage generation circuit2 of power supply circuit unit P2 and word line driver 3 of memory macroM2, and has one end connected to negative voltage supply line L0 viaswitch circuit SW2.

Negative voltage supply line L3 is connected between negative voltagegeneration circuit 2 of power supply circuit unit P3 and word linedriver 3 of memory macro 3, and has one end connected to negativevoltage supply line L0 via switch circuit SW3. Negative voltage supplyline L4 is connected between negative voltage generation circuit 2 ofpower supply circuit unit P4 and word line driver 3 of memory macro M4,and has one end connected to negative voltage supply line L0 via switchcircuit SW4.

Negative voltage supply line L5 is connected between negative voltagegeneration circuit 2 of power supply circuit unit P5 and word linedriver 3 of memory macro M5, and has one end connected to negativevoltage supply line L0 via switch circuit SW5. Negative voltage supplyline L6 is connected between negative voltage generation circuit 2 ofpower supply circuit unit P6 and word line driver 3 of memory macro M6,and has one end connected to negative voltage supply line L0 via switchcircuit SW6. Switch circuits SW2-SW6 are rendered conductive andnon-conductive when respective control signals φ2-φ6 are driven to anactivation level and an inactivation level, respectively.

In an active mode in which data writing/reading of memory macros M1-M6is allowed, control circuit 4 drives control signals ACT1-ACT6 to anactivation level and control signals φ2-φ6 to an inactivation level.Accordingly, all negative voltage generation circuits 2 of power supplycircuit units P1-P6 are rendered active and switch circuits SW2-SW6 arerendered non-conductive, whereby negative voltage VNEG is supplied tomemory macros M1-M6 via negative voltage supply lines L1-L6,respectively, from each negative voltage generation circuit 2 of powersupply circuit units P1-P6. Therefore, variation in negative voltageVNEG in each of memory macros M1-M6 can be reduced as compared to theconventional case in which one negative voltage generation circuit isprovided for a plurality of memory macros. In an active mode, one ormore of memory macros M1-M6 can be rendered active, and negative voltagegeneration circuit 2 of the power supply circuit unit corresponding tothe activated memory macro can be rendered active.

In a standby mode in which the data is maintained at memory macrosM1-M6, control circuit 4 drives control signals ACT1 and φ2-φ6 to anactivation level, and control signals ACT2-ACT6 to an inactivationlevel. Accordingly, only negative voltage generation circuit 2 of powersupply circuit unit P1 among power supply circuit units P1-P6 isrendered active and switch circuits SW2-SW6 are rendered conductive,whereby negative voltage VNEG is supplied to memory macros M1-M6 vianegative voltage supply lines L0-L6, respectively, from negative voltagegeneration circuit 2 of power supply circuit unit P1. Therefore, theamount of through current flowing to, for example, a voltage dividercircuit 5 and a detector circuit 10 in FIG. 2 can be reduced in astandby mode in which high-speed response is not necessary. Increase ofstandby current can be prevented without reduction in the operationspeed in an active mode.

Referring to the circuit block diagram of FIG. 2, negative voltagegeneration circuit 2 includes a voltage divider circuit 5, a detectorcircuit 10, a clock generation circuit 26, and a charge pump circuit 30.Voltage divider circuit 5 and detector circuit 10 function to detect thelevel of the negative voltage. Clock generation circuit 26 is renderedactive by an output signal VNEGDET of detector circuit 10. Charge pumpcircuit 30 is driven by an output clock signal CLK of a clock generationcircuit 26. The amount of through current flowing to each element islarge at the negative voltage detection circuit formed of voltagedivider circuit 5 and detector circuit 10 having high-speed response.

Specifically, voltage divider circuit 5 includes a P channel MOStransistor 6 and N channel MOS transistors 7 and 8 connected in seriesbetween the line of external power supply voltage VDD1 (for example1.2V) and the line of negative voltage VNEG (for example −0.6V). Pchannel MOS transistor 6 receives a signal VNEGCUT at its gate. SignalVNEGCUT is pulled down to an L level (logical low) of the activationlevel when the corresponding control signal ACT (for example, ACT1) isdriven to an activation level. N channel MOS transistor 7 has its gateconnected to its drain. N channel MOS transistor 8 has its gateconnected to its drain (output node N7). Each of N channel MOStransistors 7 and 8 constitutes a diode element.

When signal VNEGCUT is pulled down to an L level of activation, Pchannel MOS transistor 6 conducts, and voltage divider circuit isrendered active. Voltage VNEGDIV of output node N7 attains anintermediate voltage level (in this case 0.3V) between external powersupply voltage VDD1 and negative voltage VNEG. When signal VNEGCUT ispulled up to an H level (logical high) of inactivation, P channel MOStransistor 6 is rendered non-conductive, and voltage divider circuit 5is rendered inactive.

Detector circuit 10 includes P channel MOS transistors 11-17, N channelMOS transistors 18-21, inverters 22-24, and a stabilization capacitor25. P channel MOS transistors 11 and 12 are connected in series betweenthe line of external power supply voltage VDD1 and a node N12, receivingsignals VPCON and VNEGCUT, respectively, at their gates. Signal VPCON ispulled down to an L level of activation when a corresponding controlsignal ACT (for example, ACT1) is driven to an activation level. Pchannel MOS transistors 13 and 14 have their sources connected to nodeN12, their drains connected to nodes N13 and N14, respectively, andreceive reference voltage VREFN and output voltage VNEGDIV from voltagedivider circuit 5, respectively, at their gates. Stabilization capacitor25 is connected between the line of external power supply voltage VDD1and the gate of P channel MOS transistor 13 to prevent variation inreference voltage VREFN.

Reference voltage VREFN is generated at a reference voltage generationcircuit formed of an intermediate voltage generation circuit 40 and abuffer circuit 41, as shown in FIG. 3. Intermediate voltage generationcircuit 40 and buffer circuit 41 are provided common to negative voltagegeneration circuit 2 of power supply circuit units P1-P6, and isprovided at power supply circuit unit P1, for example. Intermediatevoltage generation circuit 40 generates an intermediate voltage VREF0(in this case, 0.6V) of external power supply voltage VDD1 (for example,1.2V). Buffer circuit 41 outputs a reference voltage VREFN (in thiscase, 0.3V) that is lower by 0.3V than output voltage VREF0 ofintermediate voltage generation circuit 40.

Referring to FIG. 2 again, N channel MOS transistors 19 and 20 havetheir drains connected to nodes N13 and N14, respectively, their gatesboth connected to node N13, and their sources both connected to the lineof ground voltage GND1. N channel MOS transistor 18 is connected betweennode N13 and the line of ground voltage GND1, receiving signal VNEGCUTat its gate. Transistors 11-14 and 18-20 constitute a comparator thatcompares the level between output voltage VNEGDIV of voltage dividercircuit 5 and reference voltage VREFN to output a signal of a levelaccording to the comparison result to output node N14.

When both signals VPCON and VNEGCUT attain an L level of activation, Pchannel MOS transistors 11 and 12 are rendered conductive and N channelMOS transistor 18 is rendered non-conductive, whereby the comparatorformed of transistors 11-14 and 18-20 is rendered active. In the casewhere output voltage VNEGDIV of voltage divider circuit 5 is higher thanreference voltage VREFN, the current flowing to transistors 13, 19 and20 becomes higher than the current flowing to transistor 14, wherebynode N14 attains an L level. In contrast, when output voltage VNEGDIV ofvoltage divider circuit 5 is lower than reference voltage VREFN, thecurrent flowing to transistors 13, 19 and 20 becomes lower than thecurrent flowing to transistor 14, whereby node N14 attains an H level.

P channel MOS transistor 15 is connected between the line of externalpower supply voltage VDD1 and node N14. P channel MOS transistors 16 and17 and N channel MOS transistor 21 are connected in series between theline of external power supply voltage VDD1 and the line of groundvoltage GND1. Signal VPCON is applied to the gate of P channel MOStransistor 16. Signal VNEGCUT is applied to the gate of P channel MOStransistor 15 via inverter 22. Transistors 17 and 21 both have theirgates connected to node N14.

When signals VPCON and VNEGCUT attain an L level, P channel MOStransistor 15 is rendered non-conductive and P channel MOS transistor 16is rendered conductive, whereby the inverter formed of transistors 17and 21 is rendered active. This inverter provides a signal that is aninverted version of the signal at node N14 at output node N17. Theoutput signal of this inverter is delayed at inverters 23 and 24 toserve as signal VNEGDET.

When signals VPCON and VNEGCUT both attain an H level, P channel MOStransistor 15 is rendered conductive and P channel MOS transistor 16 isrendered conductive, whereby the inverter formed of transistors 17 and21 is rendered inactive. Node N14 is fixed at an H level, node N17 isfixed at an L level, and signal VNEGDET is fixed at an L level. SignalVNEGDET is applied to clock generation circuit 26.

When signal VNEGDET is at an H level, clock generation circuit 26 isrendered active to output a clock signal CLK of a predeterminedfrequency. When signal VNEGDET is at an L level, clock generationcircuit 26 is rendered inactive to cease output of clock signal CLK.Clock signal CLK is applied to charge pump circuit 30.

Charge pump circuit 30 includes inverters 31-33, and P channel MOStransistors 34-39. P channel MOS transistors 34 and 36 have theirrespective sources and drains connected to each other. Each of P channelMOS transistors 34 and 36 constitute a capacitor. Clock signal CLK isapplied to the source and drain of P channel MOS transistor 34 viainverters 31 and 32, and also to the source and drain of P channel MOStransistor 36 via inverter 33. P channel MOS transistor 35 is connectedbetween an output node N35 of charge pump circuit 30 and the gate (nodeN34) of P channel MOS transistor 34, and has its gate connected to nodeN34. P channel MOS transistor 35 constitutes a diode element connectedacross nodes N35 and N34.

P channel MOS transistor 39 is connected between node N34 and the lineof ground voltage GND1, and has its gate connected to the gate (nodeN36) of P channel MOS transistor 36. P channel MOS transistor 38 isconnected between node N36 and the line of ground voltage GND1, and hasits gate connected to node N36. P channel MOS transistor 38 constitutesa diode element connected between the line of ground voltage GND1 andnode N36. P channel MOS transistor 37 is connected between node N36 andthe line of ground voltage GND1, and has its gate connected to the lineof ground voltage GND1. P channel MOS transistor 37 constitutes thediode element connected between node N36 and the line of ground voltageGND1.

FIG. 4 is a timing chart indicating an operation of charge pump circuit30. Referring to FIG. 4, it is assumed that negative voltage VNEG ismaintained at a level of −0.6V or below, signal VNEGDET is maintained atan L level, and clock signal CLK is fixed at an H level, in the initialstate. At this stage, an output signal CLKa_n of inverter 33 is at an Llevel and a clock signal CLKa of inverter 32 is at an H level. VoltageVp of node N36 corresponds to threshold voltage Vth of P channel MOStransistor 37. Voltage Vn of node N34 corresponds to 0V.

When negative voltage VNEG rises to the level of −0.5V at a certaintime, signal VNEGDET is pulled up to an H level from an L level, wherebyclock generation circuit 26 is rendered active to output clock signalCLK. When clock signal CLK is pulled down to an L level from an H level,signal CLKa_n is pulled up to an H level from an L level, whereas signalCLKa is pulled down to an L level from an H level. In response, voltageVp of node N36 rises from Vth to Vth+VDD1. P channel MOS transistor 39is rendered non-conductive. Subsequent to the fall of voltage Vn of nodeN34 to −VDD1=−1.2V from 0V, positive charge flows from node N35 to nodeN34 via P channel MOS transistor 35. Thus, Vn=VNEG−Vth=−0.5V−Vth isestablished.

Then, when clock signal CLK is pulled up to an H level from an L level,signal CLKa_n is pulled down to an L level from an H level, whereasclock signal CLKa is pulled up to an H level from an L level. Inresponse, voltage Vp of node N36 is reduced from Vth+VDD1 to Vth. Pchannel MOS transistor 39 is rendered conductive, and voltage Vn of nodeN34 attains the level of 0V. Thus, every time clock signal CLK is pulleddown to an L level from an H level, positive charge is output from nodeN35. Accordingly, voltage VNEG of node N35 is gradually reduced. Whenvoltage VNEG becomes as low as −0.6V and below, signal VNEGDET attainsan L level and clock generation circuit 26 is rendered inactive. Chargepump circuit 30 ceases its operation.

The operation set forth above can be expressed in mathematicalexpressions, as will be described hereinafter. Output voltage VNEGDIV ofvoltage divider circuit 5 is represented as VNEGDIV=VDD1/2+VNEG/2. Forexample, when external power supply voltage VDD1 is 1.2V and negativevoltage VNEG is −0.6V, VNEGDIV=0.3V is established. Therefore, bysetting reference voltage VREFN to 0.3V, negative voltage VNEG can bemaintained at −0.6V. It is to be noted that the mathematical expressionof VNEG=2*VREF−VDD1 is established, based on expression deformation,when VNEGDIV=VREFN is inserted into the aforementioned equationVNEGDIV=VDD1/2+VNEG/2.

FIG. 5 is a circuit diagram of a configuration of a memory cell includedin each of memory macros M1-M6. Each of memory macros M1-M6 includes aplurality of memory cells arranged in a plurality of rows and columns, aplurality of word lines WL provided corresponding to respectiveplurality of rows, and a plurality of bit line pairs BL, /BL providedcorresponding to respective plurality of columns. A memory cell includesP channel MOS transistors 45-48. P channel MOS transistor 45 isconnected between a corresponding bit line BL and a storage node N45,and has its gate connected to a corresponding word line WL. P channelMOS transistor 46 receives a cell plate voltage VCP (=VDD1/2) at itsgate, and has its source and drain connected to storage node N45. Pchannel MOS transistor 47 is connected between a corresponding bit line/BL and a storage node N47, and has its gate connected to acorresponding word line WL. P channel MOS transistor 48 receives cellplate voltage VCP (=VDD1/2) at its gate, and has its source and drainconnected to storage node N47. Each of P channel MOS transistors 45 and47 constitutes a transfer gate of a memory cell. Each of P channel MOStransistors 46 and 47 constitutes a capacitor.

In a write operation mode, word line WL of a selected row is set at aselect level (ground voltage VNEG), and potentials corresponding to thewrite data is applied to bit lines BL, /BL of the selected column. Forexample, when data “1” is to be written, bit lines BL, /BL are set at anH level (VDD1) and an L level (GND1), respectively. When data “0” is tobe written, bit lines BL, /BL are set at an L level and an H level,respectively. In response, P channel MOS transistors 45 and 47 arerendered conductive. The potentials of bit lines BL, /BL are writteninto storage nodes N45 and N47, respectively. When word line WL is setat a non-select level (boosted voltage VPP>VDD1), P channel MOStransistors 45 and 47 are rendered non-conductive. The potentials ofstorage nodes N45, N47, i.e. the data, are retained.

In a readout operation mode, selected word line WL attains a selectlevel after bit lines BL, /BL are precharged to the level of bit lineprecharge voltage VPRE (VDD1/2). In response, the potentials at each ofbit lines BL, /BL vary slightly according to the potentials at storagenodes N45 and N47, respectively. The small potential difference betweenbit lines BL, /BL is amplified to power supply voltage VDD1 by a senseamplifier (not shown). The potential difference between bit lines BL,/BL is read out as data, and the potentials of bit lines BL, /BL arewritten again to storage nodes N45 and N47, respectively. When word lineWL is set at a non-select level, P channel MOS transistors 45 and 47 arerendered non-conductive. Thus, a readout operation ends.

FIG. 6 is a circuit diagram of a configuration of a word line driverunitary circuit in word line driver 3 of memory macros M1-M6. Referringto FIG. 6, word line driver 3 includes a word line driver unitarycircuit provided corresponding to each word line WL. The world linedriver unitary circuit includes a P channel MOS transistor 50 and an Nchannel MOS transistor 51. P channel MOS transistor 50 receives boostedvoltage VPP at its gate, has its drain connected to a corresponding wordline WL, and receives a control signal φWL at its gate. N channel MOStransistor 51 receives negative voltage VNEG at its source, has itsdrain connected to a corresponding word line WL, and receives controlsignal φWL at its gate.

When a corresponding word line WL is selected, control signal φWL is setat an H level of the select level. In response, P channel MOS transistor50 is rendered non-conductive and N channel MOS transistor 50 isrendered conductive. Word line WL attains a select level (negativevoltage VNEG). When corresponding word line WL is not selected, controlsignal φWL is at an L level corresponding to a non-select level. Inresponse, N channel MOS transistor 51 is rendered non-conductive,whereas P channel MOS transistor 50 is rendered conductive. Word line WLis set at a non-select level (boosted voltage VPP).

Since negative voltage VNEG is used as the driving voltage of the wordline driver unitary circuit at memory macros M1-M6, high-speed responseis particularly required at negative voltage generation circuit 2. In aconventional DRAM using an N channel MOS transistor as the transfer gateof a memory cell, high-speed response at the negative voltage generationcircuit is not required since boosted voltage VPP and ground voltageGND1 are employed as the driving voltage of the word line driver unitarycircuit.

FIG. 7 is a sectional view of a configuration of a memory cell arrayincluded in each of memory macros M1-M6. Referring to FIG. 7, an N typewell NW is formed at the surface of a P type semiconductor substrate PS.A plurality of memory cells are formed at the surface of an N type wellNW. FIG. 7 shows a plurality of P channel MOS transistors 45 formed atthe surface of N type well NW. P channel MOS transistor 45 includes asource and drain (P type impurity diffusion region) formed at thesurface of N type well NW, and a gate electrode (word line WL). In orderto prevent a current flow in the forward direction at each PN junction,ground voltage GND1 is applied to P type semiconductor substrate PS,whereas external power supply voltage VDD1 is applied to N type well NW.

Memory macros M1-M6 have almost no parasitic capacitance to holdnegative voltage VNEG in the case where a negative voltage is not usedas the substrate bias voltage as in a conventional DRAM. Therefore,further high-speed response is required for negative voltage generationcircuit 2 of memory macros M1-M6. In a conventional DRAM that uses an Nchannel MOS transistor as the transfer gate of a memory cell, theparasitic capacitance of the negative voltage was so large thathigh-speed response of negative voltage was not required since an N typewell (power supply voltage) is formed at the surface of a P typesemiconductor substrate (ground voltage), a P type well (negativevoltage) is formed at the surface of an N type well, and an N channelMOS transistor of a memory cell was formed at the surface of a P typewell.

As set forth above, a negative voltage generation circuit 2 is providedat each of power supply circuit units P1-P6 for memory macros M1-M6 inthe first embodiment. As compared to the conventional case in which onlyone negative voltage generation circuit is provided for memory macrosM1-M6, the time required for the variation in negative voltage VNEG ofmemory macros M1-M6 to be propagated to detector circuit 10 of negativevoltage generation circuit 2 becomes shorter, such that the timerequired for charge pump circuit 30 of negative voltage generationcircuit 2 to supply negative current in response to the variationbecomes shorter. As a result, the response to variation in negativevoltage VNEG becomes faster. Thus, increase of negative voltage VNEG tocause delay in the operation speed in an active mode can be prevented.Since negative voltage supply lines L1-L6 for memory macros M1-M6 areconnected by switch circuits SW2-SW6, and only one of the six negativevoltage generation circuits 2 is rendered active in a standby mode,increase in standby current can be prevented.

The first embodiment is not limited to the above-described case in whichonly one of the six negative voltage generation circuits 2 is renderedactive in a standby mode. Only two, three, four or five of the sixnegative voltage generation circuits 2 may be rendered active in astandby mode. The standby current can be reduced even in such cases.Further, negative voltage VNEG can be used as the substrate biasvoltage.

FIG. 8 is a block diagram of a modification of the first embodiment,comparable to FIG. 1. This modification of FIG. 8 differs from thesemiconductor integrated circuit device of FIG. 1 in that a negativevoltage generation circuit 55 for standby is added, and all the sixnegative voltage generation circuits 2 are inactive in a standby mode.Standby negative voltage generation circuit 55 is similar to negativevoltage generation circuit 2, and includes voltage divider circuit 5,detector circuit 10, clock generation circuit 26, and charge pumpcircuit 30, shown in FIG. 2. Standby negative voltage generation circuit55 is constantly active to maintain negative voltage supply line L0 atthe level of negative voltage VNEG. It is to be noted that the throughcurrent of detector circuit 10 of standby negative voltage generationcircuit 55 is smaller than the through current of detector circuit 10 ofnegative voltage generation circuit 2. The current supply capability ofcharge pump circuit 30 of standby negative voltage generation circuit 55is lower than the current supply capability of charge pump circuit 30 ofnegative voltage generation circuit 2. Therefore, the power consumptionof standby negative voltage generation circuit 55 is smaller than thatof negative voltage generation circuit 2. Advantages similar to those ofthe first embodiment set forth above can be achieved in thismodification.

FIG. 9 is a block diagram of another modification of the firstembodiment, comparable to FIG. 1. This modification of FIG. 9 differsfrom the semiconductor integrated circuit device of FIG. 1 in thatswitch circuits SW2-SW6 are removed, and negative voltage supply linesL0-L6 are constantly conductive. This modification is advantageous inthat the layout area can be reduced corresponding to switch circuitsSW2-SW6, in addition to the advantages set forth above of the firstembodiment.

FIG. 10 is a block diagram of still another modification of the firstembodiment, comparable to FIG. 8. This modification of FIG. 10 differsfrom the semiconductor integrated circuit device of FIG. 8 in thatswitch circuits SW2-SW6 are removed, and negative voltage supply linesL0-L6 are constantly conductive. This modification is advantageous inthat the layout area can be reduced corresponding to switch circuitsSW2-SW6, in addition to the advantages set forth above of themodification of FIG. 8.

Second Embodiment

A semiconductor integrated circuit device including a DRAM using a Pchannel MOS transistor as the transfer gate of a memory cell issubjected to a burn-in test (acceleration test), likewise a conventionalDRAM, for screening early failure. In a burn-in test, a voltage higherthan that of a general level is applied. The application of negativevoltage VNEG to this type of semiconductor integrated circuit device ina burn-in test may apply excessive stress across the source and drain ofthe transistor, leading to the possibility of increasing early failure.

In view of this possibility, there is an approach to dispose an internalvoltage switch circuit 56 to switch negative voltage VNEG to groundvoltage GND in order to prevent application of excessive stress during aburn-in test, at each of power supply circuit units P1-P6, as shown inFIG. 11. Specifically, this semiconductor integrated circuit device hasnegative voltage supply lines L1-L6 provided corresponding to memorymacros M1-M6, respectively, wherein each of power supply circuit unitsP1-P6 includes a negative voltage generation circuit 2 maintaining thecorresponding negative voltage supply line at negative voltage VNEG, andan internal voltage switch circuit 56 applying ground voltage GND to thecorresponding negative voltage supply line in a burn-in test. Negativevoltage generation circuit 2 of power supply circuit units P1-P6 isrendered inactive in a burn-in test.

Since the semiconductor integrated circuit device of FIG. 11 hasinternal voltage switch circuit 56 provided at each of power supplycircuit units P1-P6, stable internal voltage GND can be supplied tomemory macros M1-M6 without having to take into account wiringresistance or the like. It is to be noted that this semiconductorintegrated circuit device is disadvantageous in that the layout area isincreased since internal voltage switch circuit 56 must be arranged ateach of power supply circuit units P1-P6.

It is to be also noted that the operating frequency in a burn-in test islow, so that the time for restoration of the voltage drop of theinternal voltage is sufficient. Therefore, internal voltage switchcircuit 56 is disposed at only power supply circuit unit P1 in thesecond embodiment, as shown in FIG. 12. Internal voltage switch circuit56 of power supply circuit unit P1 supplies ground voltage GND tonegative voltage supply lines L1-L6 via internal voltage line L7 in aburn-in test. Accordingly, increase in layout area can be suppressed.Alternatively, internal voltage switch circuit 56 may be disposed atother power supply circuit units P2-P6; instead of at power supplycircuit unit P1.

Third Embodiment

Reference voltage VREFN is supplied from one reference voltagegeneration circuit formed of intermediate voltage generation circuit 40and buffer circuit 41 to negative voltage generation circuit 2 of sixpower supply circuit units P1-P6, as shown in FIG. 3. If the referencevoltage generation circuit is disposed at power supply circuit unit P1,for example, the routing length of reference voltage line L10 thatsupplies reference voltage VREFN from the reference voltage generationcircuit to negative voltage generation circuit 2 of power supply circuitunit P6 is increased significantly, leading to the possibility of noisegeneration at reference voltage line L1. In view of this possibility,this type of semiconductor integrated circuit is provided with shieldlines 60 and 61 sandwiching reference voltage line L10 to protectreference voltage line L10 from noise as shown in FIG. 13. Shield lines60 and 61 are connected to the line of ground voltage GND 7 dedicated toshielding. Further, a stabilization capacitor 62 is provided between thetermination of reference voltage supply line L10 and the line of theexternal power supply voltage VDD7 in order to stabilize referencevoltage VREFN. The capacitance of stabilization capacitor 62 is set to avalue sufficiently larger than the parasitic capacitance of referencevoltage line L10 (for example, ten times larger). This stabilizationcapacitor 62 reduces the noise of reference voltage line L10 to a levelof 1/10 or below. Further, the noise applied to reference voltage lineL1 from negative voltage generation circuit 2 is also alleviated.Stabilization capacitor 62 is to be formed of a gate capacitor or thelike provided between the gate of a transistor and a substrate or well.

Detector circuit unit 63 includes voltage divider circuit 5 and detectorcircuit 10 of FIG. 2, and sets signal VNEGDET to an H level and an Llevel when negative voltage VNEG is higher and lower, respectively, thantarget voltage 2V1−VDD (where V1=VREFN). Pump circuit unit 64 includesclock generation circuit 26 and charge pump circuit 30 of FIG. 2, and isrendered active when signal VNEGDET is at an H level to supply negativecharge to negative voltage supply line L6 (output positive charge), andrendered inactive when signal VNEGDET is at an L level to cease supplyof negative charge. Detector circuit unit 63, pump circuit unit 64, andmemory macro M6 are connected to the line of external power supplyvoltage VDD6 for power supply circuit unit P6 and memory macro M6.

FIG. 14 is a timing chart of the level variation of external powersupply voltages VDD6 and VDD7, reference voltage VREFN, ground voltageGND7, and negative voltage VNEG. External power supply voltages VDD6 andVDD7 having the same level are supplied from different power supply padsand lines. When negative voltage generation circuit 2 and memory macroM6 operate, current is consumed so that external power supply voltageVDD6 is reduced to the level of VDD−V2, for example. However, externalpower supply voltage VDD7 dedicated to shielding exhibits little or novariation. Since external power supply voltage VDD7 hardly varies, levelV1 of reference voltage VREF is also constant, and negative voltage VNEGdoes not change from the level of 2V1−VDD. Therefore, there is a problemthat the level of drive voltage VDD6−VNEG is reduced from the level of 2(VDD−V1) to 2 (VDD−V1)−V2, resulting in lower operation speed at memorymacro M6.

In view of this problem, one electrode of stabilization capacitor 62 isconnected to the line of external power supply voltage VDD6 for powersupply circuit unit P6 and memory macro M6, instead of the line ofexternal power supply voltage VDD7 dedicated to shielding, as shown inFIG. 15 in the third embodiment. Accordingly, when external power supplyvoltage VDD6 is reduced to VDD−V2, reference voltage VREFN is reduced tothe level of V1−V2′, and negative voltage VNEG is reduced to the levelof 2V1−VDD−V2′, as shown in FIG. 16. Here, V2≈V2′ is established, sincethe capacitance of stabilization capacitor 62 is sufficiently largerthan the parasitic capacitance of reference voltage line L10. Therefore,even if external power supply voltage VDD6 is reduced, drive voltageVDD6−VNEG of memory macro M6 is maintained at the level of substantially2 (VDD−V1), so that the operation speed of memory macro M6 will not bedegraded. Although the above description is based on memory macro M6,the same applies to other memory macros.

Fourth Embodiment

FIG. 17 is a circuit block diagram of a main part of this type ofsemiconductor integrated circuit device. In this semiconductorintegrated circuit device of FIG. 17, reference voltage VREF generatedat the reference voltage generation circuit (not shown) is supplied to aVDC (Voltage Down Converter) circuit 73 in power supply circuit unit P6via reference voltage line L11.

In this semiconductor integrated circuit, shield lines 70 and 71 areprovided to sandwich reference voltage line L11 in order to protectreference voltage line L11 from noise. Shield lines 70 and 71 areconnected to the line of ground voltage GND7 dedicated to shielding. Astabilization circuit 72 is provided between the termination ofreference voltage supply line L11 and the line of ground voltage GND7 inorder to stabilize reference voltage VREF. The capacitance ofstabilization capacitor 72 is set to a value sufficiently larger thanthe parasitic capacitance of reference voltage line L11 (for example,ten times larger). Stabilization capacitor 72 reduces the noise atreference voltage line L11 to a level of 1/10 or below, and alsoalleviates noise from VDC circuit 73.

VDC circuit 73 includes a comparator 74 and a P channel MOS transistor75. As shown in FIG. 18, comparator 74 includes P channel MOStransistors 80 and 81, and N channel MOS transistors 82-84. P channelMOS transistors 80 and 81 have their sources both connected to the lineof external power supply voltage VDD6, their drains connected to nodesN80 and N81, respectively, and their gates both connected to a node N81.P channel MOS transistors 80 and 81 constitute a current mirror circuit.Signal COMP at node N80 is the output signal of comparator 74. N channelMOS transistors 82 and 83 have their drains connected to nodes N80 andN81, respectively, receive reference voltage VREF and internal powersupply voltage intVDD, respectively, at their gates, and have theirsources connected to a node N84. N channel MOS transistor 84 isconnected between node N84 and the line of ground voltage GND6, andreceives control signal BIASL at its gate. P channel MOS transistor 75is connected between the line of external power supply voltage VDD6 andthe line of internal power supply voltage intVDD, and receives outputsignal COMP from comparator 74 at its gate.

When control signal BIASL attains an H level, N channel MOS transistor84 conducts and comparator 74 is rendered active. When internal powersupply voltage intVDD is lower than reference voltage VREF, the currentflowing to transistors 80, 81 and 83 becomes smaller than the currentflowing to transistor 82 to cause signal COMP to attain an L level. Pchannel MOS transistor 75 conducts and internal power supply voltageintVDD rises. In contrast, when internal power supply voltage intVDD ishigher than reference voltage VREF, the current flowing to transistors80, 81 and 83 becomes larger than the current flowing to transistor 82to cause signal COMP to attain an H level. P channel MOS transistor 75is rendered non-conductive and internal power supply voltage intVDD isreduced. Therefore, internal power supply voltage intVDD becomes equalto reference voltage VREF.

Internal power supply voltage intVDD is applied to memory macro M6. VDCcircuit 73 and memory macro M6 are connected to the line of groundvoltage GND for power supply circuit unit P6 and memory macro M6. Memorymacro M6 is driven by the difference in level between internal powersupply voltage intVDD and ground voltage GND6.

FIG. 19 is a timing chart representing the level variation in powersupply voltage VREF, internal power supply voltage intVDD, and groundvoltages GND6 and GND7. Ground voltages GND6 and GND7 having the samelevel are supplied from different power supply pads and lines. When VDCcircuit 73 and memory macro M6 operate, current flows in such thatground voltage GND6 rises to, for example, GND+V2. However, groundvoltage GND7 dedicated to shielding exhibits little or no variation.Since there is little or no variation in ground voltage GND7, level V1of reference voltage VREF is also constant, and the level of internalpower supply voltage intVDD does not vary from V1. Therefore, there is aproblem that drive voltage intVDD−GND6 is reduced to the level of V1-V2from V1 at memory macro M6, leading to the problem that the operationspeed is reduced.

In view of this problem, one electrode of stabilization capacitor 72 isconnected to the line of ground voltage GND6 for power supply circuitunit P6 and memory macro M6, instead of the line of ground voltage GND7dedicated to shielding, in the fourth embodiment, as shown in FIG. 20.Accordingly, when ground voltage GND6 rises to GND+V2, reference voltageVREF rises to the level of V1+V2′, and internal power supply voltageintVDD also rises to the level of V1+V2′, as shown in FIG. 21. Here,V2≈V2′ is established since the capacitance of stabilization capacitor72 is sufficiently larger than the parasitic capacitance of referencevoltage line L11. Therefore, even if ground voltage GND6 rises at memorymacro M6, drive voltage intVDD−GND6 of memory macro M6 is maintained atsubstantially V1, so that the operation speed of memory macro M6 willnot be degraded.

Fifth Embodiment

FIG. 22 is a block diagram of a configuration of a semiconductorintegrated circuit device according to a fifth embodiment of the presentinvention. Referring to FIG. 22, the semiconductor integrated circuitdevice has a plurality (six in the drawing) of memory macros M1-M6arranged in three rows and two columns at the surface of semiconductorsubstrate 1. Power supply circuit units P1-P6 are arranged adjacent tomemory macros M1-M6, respectively. A reference voltage generationcircuit 76 is arranged at each of power supply circuit units P1-P6.Reference voltage generation circuit 76 of each of power supply circuitunits P1-P6 generates a respective one of reference voltagesVREF1-VREF6, and supplies the reference voltage to VDC circuit 73, forexample, in corresponding power supply circuit units P1-P6.

As shown in FIG. 23, reference power supply lines 80 are provided atpower supply circuit units P1-P6 to supply reference voltagesVREF1-VREF6, respectively. Also shield lines 81 and 82 are provided soas to sandwich each reference voltage line 80. Ground voltagesGND11-GND16 dedicated to shielding are provided to shield lines 81 and82 of power supply circuit units P1-P6, respectively.

Since reference voltage generation circuit 76, reference voltage line80, and shield lines 81 and 82 are provided for each of power supplycircuit units P1-P6 in the fifth embodiment, the resistance of shieldlines 81-82 can be reduced. Therefore, the level of noise N at the linesof ground voltages GND11-GND16 of shield lines 81 and 82 to the farthestpoint can be suppressed to a low level.

Sixth Embodiment

FIG. 24 is a block diagram of a configuration of a semiconductorintegrated circuit device according to a sixth embodiment of the presentinvention, comparable to FIG. 22. The semiconductor integrated circuitdevice of FIG. 24 differs from the semiconductor integrated circuitdevice of FIG. 22 in that reference voltage generation circuit 76 isdisposed at only power supply circuit unit P1, and reference voltageVREF generated at reference voltage generation circuit 76 is supplied toall power supply circuit units P1-P6 via reference voltage line 80.Shield lines 81 and 82 are provided so as to sandwich reference voltageline 80. As shown in FIG. 25, ground voltage GND1 dedicated to shieldingis applied to shield lines 81 and 82 at power supply circuit unit P1.

Since reference voltage generation circuit 76, reference voltage line80, and shield lines 81 and 82 are provided common to power supplycircuit units P1-P6 in the sixth embodiment, the layout area can bereduced as compared to that of the fourth embodiment.

It is to be noted that, when the number of memory macros is increased,the resistance of shield lines 81 and 82 becomes larger, so that noise Nof shield lines 81 and 82 from the line of ground voltage GND11 to thefarthest point becomes higher. In this case, shield lines 81 and 82 areto be connected at a plurality of sites (two sites in the drawing) tothe lines of ground voltages GND11 and GND12 for shielding, as shown inFIG. 26. Further, as shown in FIG. 27, shield lines 81 and 82 can bedivided into six sets of shield lines 81.1, 82.1; . . . ; 81.6, 82.6corresponding to power supply circuit units P1-P6. The six sets ofshield lines 81.1, 82.1; . . . ; 81.6, 82.6 may be connected to thelines of ground voltages GND11-GND16, respectively, dedicated toshielding. Accordingly, the level of noise N can be suppressed at a lowlevel.

Seventh Embodiment

FIG. 28 is a block diagram of a configuration of this type ofsemiconductor integrated circuit device. Referring to FIG. 28, thesemiconductor integrated circuit device includes a semiconductorsubstrate 1, six memory macros M1-M6 arranged in three rows and twocolumns at the surface thereof, power supply circuit units P1-P6provided adjacent to memory macros M1-M6, respectively, in the Xdirection, a logic circuit 90 arranged at the region between memorymacros M1-M6 and power supply circuit units P1-P6, a plurality of powersupply voltage lines 91 for logic, a plurality of ground voltage lines92 for logic, three power supply voltage lines 93 for memory, threeground voltage lines 94 for memory, a plurality of power supply voltagepads 95 for logic, a plurality of ground voltage pads 96 for logic, aplurality of power supply voltage pads 97 for memory, a plurality ofground voltage pads 98 for memory, and a plurality of signal pads 99.

Each of lines 91-94 extends in the X direction in the drawing. Pads95-99 are arranged in the Y direction in the drawing at respective endsof substrate 1. Each logic power supply voltage line 91 receivesexternal power supply voltage from logic power supply voltage pad 95,and supplies the received external power supply voltage to logic circuit90. Each logic ground voltage line 92 receives external ground voltagefrom logic ground voltage pad 96, and supplies the received externalground voltage to logic circuit 90. The three memory power supplyvoltage lines 93 receive external power supply voltage from memory powersupply voltage pad 97 to supply the received external power supplyvoltage to the three sets of memory macros, and power supply circuitunits M1, P1, M2, P2; M3, P3, M4, P4; M5, P5, M6, P6, respectively. Thethree memory ground voltage lines 94 receive external ground voltagefrom memory ground voltage pad 98 to supply the received external groundvoltage to the three sets of memory macros and power supply circuitunits M1, P1, M2, P2; M3, P3, M4, P4; M5, P5, M6, P6. Signal pad 99 isused to input and/or output a signal between the semiconductorintegrated circuit device and an external source.

Since two sets of memory macros and power supply circuit units, i.e. M1,P1, and M2 and P2; M3, P3 and M4, P4; and M5, P5 and M6, P6, share onememory power supply voltage line 93 and one memory ground voltage line94 in this semiconductor integrated circuit device, the voltage drop ateach memory power supply voltage line 93 and the voltage rise at eachmemory ground voltage line 94 are increased, leading to the problem thatthe circuit characteristics are degraded.

In view of this problem, the surface of substrate 1 is divided into sixregions in the Y direction, as shown in FIG. 29 in the seventhembodiment. At each of the six regions are provided six sets of memorymacros and power supply circuit units M1, P1; . . . ; M6, P6. Memorypower supply voltage line 93 and memory ground voltage line 94 areprovided corresponding to each set of the six memory macros and powersupply circuit units M1, P1; . . . ; M6, P6. Accordingly, the voltagedrop at each memory power supply voltage line 93 and voltage rise ateach memory ground voltage line 94 are reduced in the presentsemiconductor integrated circuit device, allowing suppression indegradation of the circuit characteristics.

A plurality of the embodiments among the first to seventh embodimentsset forth above may be combined appropriately.

Although the present invention has been described and illustrated indetail, it is clearly understood that the same is by way of illustrationand example only and is not to be taken by way of limitation, the spiritand scope of the present invention being limited only by the terms ofthe appended claims.

1. A semiconductor device comprising: a plurality pf negative voltage supply lines connected in common, a plurality of negative voltage detection circuits provided corresponding to said plurality of negative voltage supply lines, respectively, each providing a first activation signal when a voltage of a corresponding negative voltage supply line is higher than a predetermined negative voltage, a plurality of negative charge supply circuits provided corresponding to said plurality of negative voltage supply lines, respectively, each supplying negative charge to a corresponding negative voltage supply line when said first activation signal is output from a corresponding negative voltage detection circuit, a plurality of memory circuits provided corresponding to said plurality of negative voltage supply lines, respectively, each receiving said negative voltage from a corresponding negative voltage supply line, allowing a data write/read operation independently, and a control circuit rendering a first number of negative voltage detection circuits active among said plurality of negative voltage detection circuits in an active mode, and rendering a second number of negative voltage detection circuits active in a standby mode, said second number lower than said first number.
 2. The semiconductor according to claim 1, further comprising: a negative voltage detection circuit for standby, rendered active at least in a standby mode, driven by a drive current lower than the drive current of said negative voltage detection circuit to output a second activation signal when the voltage of said plurality of negative voltage supply lines is higher than said predetermined negative voltage, and a negative charge supply circuit for standby, supplying negative charge to said plurality of negative voltage supply lines when said second activation signal is output from said voltage detection circuit for standby, wherein said control circuit renders one or more of said plurality of negative voltage detection circuits active in an active mode, and renders said plurality of negative voltage detection circuits inactive in said standby mode.
 3. The semiconductor device according to claim 1, further comprising a switch circuit provided between said plurality of negative voltage supply lines for electrically disconnecting each negative voltage supply line from other negative voltage supply lines in said active mode, and connecting in common said plurality of negative voltage supply lines in said standby mode.
 4. A semiconductor device comprising: a plurality of negative voltage supply lines, a plurality of negative voltage generation circuits provided corresponding to said plurality of negative voltage supply lines, respectively, each rendered active in a normal operation mode to maintain a corresponding negative voltage supply line at a predetermined negative voltage, and rendered inactive in a burn-in test mode, a voltage switch circuit provided common to said plurality of negative voltage supply lines for applying a ground voltage to said plurality of negative voltage supply lines in said burn-in test mode, and a plurality of memory cells provided corresponding to said plurality of negative voltage supply lines, respectively, each receiving said negative voltage and said ground voltage from a corresponding negative voltage supply line.
 5. A semiconductor device comprising: a reference voltage generation circuit generating a reference voltage, a reference voltage line receiving the reference voltage generated at said reference voltage generation circuit, a shield line provided along said reference voltage line, a power supply voltage line receiving a power supply voltage, a stabilization capacitor having one electrode connected to said reference voltage line and another electrode receiving said power supply voltage from said power supply voltage line, a negative voltage generation circuit driven by said power supply voltage from said power supply voltage line, and receiving said reference voltage from said reference voltage line to generate a negative voltage based on the received reference voltage, and an internal circuit driven by said power supply voltage from said power supply voltage line and the negative voltage generated at said negative voltage generation circuit.
 6. A semiconductor device comprising: a reference voltage generation circuit generating a reference voltage, a reference voltage line receiving the reference voltage generated at said reference voltage generation circuit, a shield line provided along said reference voltage line, a ground voltage line receiving a ground voltage, a stabilization capacitor having one electrode connected to said reference voltage line and another electrode receiving said ground voltage from said ground voltage line, an internal voltage generation circuit driven by a power supply voltage and said ground voltage from said ground voltage line, and receiving said reference voltage from said reference voltage line to generate an internal voltage based on the received reference voltage, and an internal circuit driven by the internal voltage generated at said internal voltage generation circuit and said ground voltage from said ground voltage line.
 7. A semiconductor device comprising: a reference voltage generation circuit generating a reference voltage, a reference voltage line receiving the reference voltage generated at said reference voltage generation circuit, a shield line provided along said reference voltage line, and receiving a ground voltage, an internal voltage generation circuit receiving said reference voltage from said reference voltage line to generate an internal voltage based on the received reference voltage, and an internal circuit driven by the internal voltage generated at said internal voltage generation circuit.
 8. A semiconductor device comprising: a reference voltage generation circuit generating a reference voltage, a reference voltage line receiving the reference voltage generated at said reference voltage generation circuit, a shield line provided along said reference voltage line, and receiving a ground voltage, a plurality of internal voltage generation circuits arranged in an extending direction of said reference voltage line, each receiving said reference voltage from said reference voltage line to generate an internal voltage based on the received reference voltage, and a plurality of internal circuits provided corresponding to said plurality of internal voltage generation circuits, respectively, each driven by the internal voltage generated at a corresponding internal voltage generation circuit.
 9. A semiconductor device comprising: a reference voltage generation circuit generating a reference voltage, a reference voltage line receiving the reference voltage generated at the reference voltage generation circuit, a plurality of internal voltage generation circuits arranged in an extending direction of said reference voltage line, each receiving said reference voltage from said reference voltage line to generate an internal voltage based on the received reference voltage, a plurality of shield lines provided corresponding to said plurality of internal voltage generation circuits, respectively, each provided along said reference voltage line, and receiving a ground voltage, and a plurality of internal circuits provided corresponding to said plurality of internal voltage generation circuits, respectively, each driven by the internal voltage generated at a corresponding internal voltage generation circuit.
 10. A semiconductor device comprising: a substrate having a surface divided into a plurality of regions in a first direction, a plurality of memory circuits provided at said plurality of regions, respectively, a plurality of power supply voltage lines provided corresponding to said plurality of memory circuits, respectively, each extending in a second direction orthogonal to said first direction to supply a power supply voltage to a corresponding memory circuit, and a plurality of ground voltage lines provided corresponding to said plurality of memory circuits, respectively, each extending in said second direction to supply a ground voltage to a corresponding memory circuit. 